The present invention relates to the harvesting of seeds from soil crops and especially to the stripping of seeds from a standing crop while leaving the stems of the crop attached to the ground.
Some soil crops, such as wheat for example, have traditionally been harvested by combines which cut and collect the standing stalks with the head of grain attached, and thereafter separate the grain seeds from the chaff. Although effective, such combines are quite large and costly, due in large part to the high power requirements and the need for providing a separating mechanism capable of separating and handling the large amounts of chaff which are collected.
Other soil crops, such as grass seed for example, have been harvested by machines which employ one or more rotary brushes or other tined rollers which are intended to beat or pull the seeds from the stems. The removed seeds are impelled to a collecting zone, possibly with the aid of an air suction or blowing mechanism. Exemplary of such structures are the disclosures in U.S. Pat. Nos. 1,134,443 issued to Engle on Apr. 6, 1915; 1,206,409 issued to Bruce on Nov. 28, 1916; and 2,460,029 issued to Ramp on Jan. 25, 1949.
Harvesters of that kind may include a pair of axially transverse brush-type rotors which form a bite therebetween within which the crop heads are to be acted upon as the harvester traverses a field. In this regard, the brush bristles rub against the seeds within the bite and strip the seeds from the crop heads. Upon being stripped, the seeds are conveyed to a collecting zone. Among the problems which would expectedly be encountered by such a harvester is the need to establish an optimum cooperative or interacting relationship between the crop heads and the rotors as regards crop head orientation and rotor speed, for example, to maximize the effectiveness of seed removal. It is also necessary to provide a seed conveyance technique which minimizes the loss of stripped seeds. It has been proposed to employ one or more air streams for conveying the seeds to the collecting zone and/or for bending the standing crop into the bite. While such expedients seem promising, commercial success has yet to be achieved.
Numerous other grain harvesters have been proposed which involve a rotary beater intended to strike the grain heads in some fashion to separate the grain from the stalk. Exemplary of such machines are the disclosures in the following U.S. Pat. Nos. 1,146,785 issued to Colahan on July 20, 1915; 2,485,713 issued to Dowd on Oct. 25, 1949; 2,499,047 issued to Wilkins on Feb. 28, 1950; 2,693,072 issued to Belzer et al on Nov. 2, 1954; 2,706,373 issued to Nisbet on Apr. 19, 1955; 2,853,845 issued to Smith on Sept. 30, 1958; 3,184,905 issued to Hillier on May 25, 1965; and French Pat. No. 1,240,440 issued Nov. 17, 1959. However, none of those proposals has achieved commercial success.